Last Stone Weight

import heapq

class Solution:
    def lastStoneWeight(self, stones: List[int]) -> int:
        # 1) Heapify the stones input
        # Use negative elements to simulate a max heap, because
        # Python's heapq implementation makes a min heap by default.
        heap = [-elem for elem in stones]
        heapq.heapify(heap)

        # 2) While heap length > 1
        while len(heap) > 1:
            # Heap pop twice
            heaviest1 = -heapq.heappop(heap)
            heaviest2 = -heapq.heappop(heap)

            # Smash
            remainder = heaviest1 - heaviest2

            # If remainder > 0
            if remainder > 0:
                # Heap push it
                heapq.heappush(heap, -remainder)

        # 3) Return what's left in heap, if any.
        if len(heap) == 1:
            return -heap[0]

        # If nothing in heap, return 0.
        return 0